Assalam Alikum W.r.b brother,
الجواب وبالله التوفيق
If such pipes are manufactured and only used for using (intoxicants or) drugs then it is considered impermissible to sell them and will be considered as an act of helping or assisting the drug users. Due to it being assistance of a haram act it will be considered haram as well.
If however, these pipes are used for consuming drugs as well as non-intoxicants then it will be permissible to sell them. In this case, the person who uses it for doing drugs will be held responsible for his actions solely. This is still not something which is free of karahiyat(i.e. something which is disliked or detested or makrooh in other words).
والثالث بیع اشیاء لیس لھا مصرف الا فی المعصیۃ فیتمحض بیعھا واجارتھا وان لم یصرح ففی جمیع ھذہ الصور قامت المعصیۃ بعین ھذا العقد والعاقد ان کلاھما اٰثمان بنفس العقد سواء یستعمل بعد ذلک فی المعصیۃ ام لا –
(حاشیہ فتاوی محمودیہ، ص 178، ج24، بحوالہ جواہر الفقہ)
وجاز بیع عصیر عنب ممن یتخذ خمر الان المعصیۃ لا تقوم بعینہ بل بعد تغیرہ وقیل یکرہ لاعانتہ علی المعاصی
(حاشیہ فتاوی محمودیہ، ص 179، ج24، بحوالہ در مختار)
واللہ اعلم بالصواب